Matt R. Siegfried (Department of Geophysics, Colorado School of Mines, Golden, CO, United States); Laurie Padman (Earth and Space Research, Corvallis, OR, United States); Tasha Snow (NASA Goddard Space Flight Center and ESSIC, University of Maryland, United States); Zachary S. Katz (Department of Geophysics, Colorado School of Mines, Golden, CO, United States); Ellie Abrahams (Stanford University, Stanford, CA, United States)

About fifty percent of the mass loss from the Antarctic Ice Sheet occurs through iceberg calving along the fronts of Antarctic ice shelves, the floating extensions of glaciers. Most of these icebergs form through the extension of rifts (crevasses extending through the full thickness of the ice shelf), emphasizing the importance of mapping existing rifts and monitoring three-dimensional changes in rift geometry. SWOT is the first altimetry mission with the potential to map ice shelf rifts at sub-kilometer scales, both along- and across-track, on at least monthly time scales regardless of cloud cover. SWOT’s swaths extend south to a latitude limit of about 78 degrees, which covers many of the most rapidly changing ice shelves. In the fall of 2024, the SWOT Cryosphere Working Group developed a High-Resolution (HR) acquisition mask targeting several major Antarctic ice shelves at varying degrees of swath overlap set by downlink constraints. Here, we demonstrate the potential, and current limitations, of SWOT rift mapping using HR 100-m Raster data. We use along-track ICESat-2 laser altimetry measurements, advected to account for lateral ice motion between the time-separated SWOT and ICESat-2 records, as precise validation data for SWOT’s elevation accuracy. Examples from several ice shelves with different surface characteristics are used to explore the strengths and limitations of SWOT mapping of rifts, and to demonstrate the symbioses between SWOT and ICESat-2 missions for ice shelf studies.